Hello.. I am doing one project in which msg from GSM is read and it is Displayed to LCD. but microcontroller 89v51 and GSM900A does not communicate every time.. sometimes it successfully happen that AT command from microcontroller is send to GSM and message from any no. to GSM is Displayed to LCD.. bt it's not happening everytime.. i am not getting the solution, Please help.. I have connect 12V,2A supply to GSM.. Microcontroller Rx pin connected to Tx of GSM.. Microcontroller Tx pin Connected to Rx of GSM.. and Ground to Ground.. Please help me. what may be the problem? and how should i fix that.
Is the Proteus approach working well for your programming/debugging style?
You'd use a Microsoft or GNU C compiler, the serial port access could be abstracted via a couple of subroutines so ostensibly the same core code could be run on the PC or 8051.
Get the automation and interaction figured out without the circus of a black box you have minimal internal visibility into.
Note that the uVision simulator can direct its simulated UART output to a COM port, and can receive input from a COM port into the simulation:
www.keil.com/.../uv4cl_sm_uartcommunication.htm
See: www.avrfreaks.net/.../2306116
And: www.avrfreaks.net/.../2417261